Effects of atmospheric gases on terrestrial plants and critical levels of air pollution

An integrated approach was developed to determine the critical levels of air pollution for ecological standard setting based on the unified index of biological response, by taking into account the effects of all pollution components simultaneously. An empirical model of plant productivity was taken as the dose response model for gaseous pollutant effect on the productivity of trees and the annual productivity of plants was used as the above mentioned index. The CO2 increase in the lower atmosphere was considered to potentially increase plant productivity and NO2 was estimated as neutral while being dangerous for plants as a chemical precursor of ozone or as a source of acidification. The maximum permissible chronic O3 and SO2 levels for trees were estimated and it was found that O3 is much more phytotoxic, as compared to SO2 , with a rather narrow range of permissible levels (27-33 ppb) which complicates its monitoring and control.     

Fluoride distibution and the effect of some ions along Alexandria coastal Mediterranean seawater of Egypt

The coastal seawater of Mediterranean of Alexandria receives large amount of discharged waters containing industrial wastes, sewage, and agricultural and domestic drainage. Fluoride and some parameters were(chemical and physical) determined. The data gave indication that the content and the amount of the discharged water largely affect the chemical composition of the coastal water. Stepwise regression analysis was highly significant and the model was very fruitful, where the observed and calculated values were mostly concordant. This may indicated that there was a relation between fluoride content in coastal seawater and its content in the discharged water.     

用法律、用技术征服二氧化硫的污染（续二）

顾名思义，烟气脱硫是一种用物理或化学的方法对燃料燃烧后的烟气进行处理而除去二氧化硫的方法；英文缩写名为FGD。这种方法的研究始于一百多年前的1850年。烟气中的硫主要是以二氧化硫的形态存在，脱硫看似简单，但因其烟气量极大，而二氧化硫浓度又非常低(大多在0．5％以下，如25万     

城市污水处理厂污泥沉降影响因素研究

研究总结了目前城市污水处理厂污泥沉降影响的因素，概括总结了pH值、溶解氧、温度、盐度等环境因素以及磁场等外部环境因素对不同性状污泥的沉降影响。为污泥沉降脱水最佳条件提供了研究思路，也为污泥后续机械脱水提供了基础。     

气提式循环反应器生物膜与游离活性污泥的对比试验探讨

通过对气提式循环反应器处理污水中载体生物膜和游离活性污泥的对比试验，分析指出：活性污泥有利于有机物的去除和混合液的沉降性；生物膜的存在，增加了生物量，提高了处理效率，且是硝化的主要原因     

用法律、用技术征服二氧化硫的污染（续一）

据有关资料分析,人为引起的二氧化硫排放,主要来源是煤,其次是石油,而其他方面所占的比例是相当小的。 , 我国是以煤为主要燃料的发展中国家,据1986年资料,煤在能源生产构成中占76％,石油占17.1％。而我国的江西、贵州、四川、山东、陕西、浙江等省各煤矿的燃煤含硫量相当高,含硫量大多在3％左右,有的高达5％以上。     

铜山口铜(钼)矿床成矿流体水-岩反应数值模拟

铜山口铜(钼)矿床位于湖北省大冶市境内,是一典型的矽卡岩-斑岩复合型矿床。通过对其流体包裹体的系统研究,确定了成矿阶段成矿流体的成分及温压条件,并结合矿床学研究,将成矿过程分解为两个平行的成矿阶段,即矽卡岩型矿化阶段和斑岩型矿化阶段。根据Johson和Reed等人建立的水 岩反应模型,对本矿床成矿流体与围岩反应并析出金属沉淀的过程进行了数值模拟计算,其结果与实际地质情况吻合较好。     

Status of air pollution in Beijing

A study has been made on elements organic constituents, TSP, SO2,NO2 of atmospheric pollutants in Beijing. 17 elements, and some PAHs, e. g. B(a)P, B(b, j, k)P, and B(g, h, i)P, in airborne particles by X-ray fluorescence spectroscopy and HPLC, GC/MS, have been determined respectively. It has been shown that the elements Pb, Zn, S and Cu were more enriched in fine particles and different valence states of sulfur at various sites. It was found that the concentrations of S6+ and S2-were more than 85% and less than 15% of the total sulfur respectively. Concentrations of major PAHs and sulfur-containing compounds increased in winter and in urban area. High values for Pb and Zn in city, Fe and Mn at industrial area and Cu, Al rural sites were obtained respectively. This implies the functions of different elemental sources of various sites. Thus, elements can be from distingushed anthropogenic and natural sources.The main contribution of SO2 was found of to have same seasonal variation as the anthropogenic el